Background & Aims: Lung cancer is the most common cancer in men and the main cause of male cancer deaths worldwide. Also, it is the second leading cause of cancer deaths in women worldwide. In this study, we replaced miRNA145 in lung cancer cells by vector based miRNA-145, then the level of miRNA expression in these cells increased and we investigated the effects of the miRNA on inhibition of metastasis.Materials & Methods: After A549 cell line culturing, we obtained IC50 of Genticin antibiotic (G418) by using MTT test. In the following miRNA-145 was transferred into lung cancer cells, by using JetPAI. QRT-PCR test was used to confirm the transfer of miRNA-145 into cells. We use wound healing test to check the immigration status of transfected cells and control cells.Results: By using MTT test, the IC50 of Genticin antibiotic was obtained 494.1 µg/ml. The results of the qRT-PCR test showed the increased expression level of miRNA-145 in A549 transfected cells. The wound healing test results showed migration reduction of transfected cells compared to control cells.Conclusion: The results that we obtained shows that increasing miRNA-145 expression level has a role in the reduction of metastasis at lung cancer cell line A549.